1. Field of the Invention
The present invention relates to a variable direction of view endoscope, and more particularly to an endoscope that changes a direction of view by moving an optical element provided at a distal end portion of an insertion portion.
2. Description of the Related Art
Endoscopes for picking up an optical image, which can be introduced from outside to inside of a living body or structure in order to observe a site such as inside of the living body or an inner portion of the structure where observation is difficult, have been used in medical fields or industrial fields, for example.
Endoscopes have a type including a flexible insertion portion used for examination and treatment of digestive tracts, and a type including a rigid insertion portion used for surgical operation.
Specifically, the endoscope having the rigid insertion portion is called a rigid endoscope, a laparoscope, a pyeloureteroscope, or the like, and as disclosed in Japanese Patent Application Laid-Open Publication No. 2010-29658, for example, a swing prism endoscope is known in which an optical axis is swung by swinging to tilt the prism of the optical element provided at the distal end, to allow the view (perspective angle) to be changed.